Cigarette machine tapes



United States Patent 3,234,040 CIGARETTE MACHINE TAPES John JamesKirwan, Hillside, England, assignor, by mesne assignments, to Brown andWilliamson Tobacco Corporation, Lonisville, Ky., a corporation ofDelaware Ne Drawing. Filed July 13, 1961, Ser. No. 124,312 Claimspriority, application Great Britain, July 15, 1969, 24,7 69/ 60 1 Claim.(Cl. 117-76) This invention concerns improvements relating tocigarette-machine tapes, that is the conveyor tapes employed incigarette-making machines. These tapes, which are usually endless woventapes with cotton weft and linen-fibre warp, commonly travel through thepressure unit, tongue piece and garniture at about 275 feet per minute.The tape is subject to heat and friction in the garniture and also to analternating flexing action. In addition, some of the ink from theprinting on the cigarette paper offsets on to the upper face of the tapeand causes the fibres to rot. As a result, the working life of such tapeis very short. In addition, the pressure of the tape against the papertends to produce so-called tape marks, i.e. a more or less pronouncedembossed weave appearance. The present invention accordingly seeks toimprove the working life of the tape and to reduce tape marks on thecigarettes.

According to the invention, cigarette-machine tape is first treated withan application of microcrystalline wax for lubricating its internalfibres and is then given an external coating of a lacquer. By using thiscombination of media, a considerably improved working life, for examplea three-fold increase can be obtained without it being necessary toemploy an excessive amount of wax, such as would involve risk ofwax-staining of the cigarettes in passing through the hot garniture. Atthe same time, the rotting effect of the drying ink from the cigaretteprint is resisted by the lacquer. The latter is preferably a solution ofa copolymer of vinyl chloride/ acetate resin, which has been found topossess very good resistance to wear and to ink, but other syntheticresin or nitro cellulose lacquers may be employed.

A preferred manner of carrying the invention into effect will now bemore fully described.

The cigarette-machine tapes are first immersed in a solution of amicrocrystalline wax in a volatile solvent for the wax, preferablycarbon tetrachloride, using 5 g. of a microcrystalline wax in 100 g. ofsolution from which the tapes absorb approximately /2 to 1 g., dependingon the size of the tape treated. For this purpose, the tapes are placedin baskets and lowered, in a fume cabinet, into the solution, held at atemperature of 120 F., for a period of say, four minutes. Duringimmersion, the window of the cabinet is closed and an extractor assistsin removing fumes rising from the solvent. When the tapes are removedfrom the solution, they are laid on a draining board within the cabinetfor a few 3,234,941 Patented Feb. 8, 1966 minutes. As the carbontetrachloride evaporates, the tapes become whiter and the operator canjudge by the degree of whiteness when they can be taken from the cabinetand hang on racks to dry by airing overnight.

On the following day, the tapes are coated on one side with the coatingmaterial which is evenly distributed thereon.

When the tapes have been coated on one side, they are dried. This may beeffected by hanging them on hooks 1 of the revoluble carrier of a dryingmachine. After the tapes have been thus dried, each tape is turned andthe uncoated side is then coated and dried in the drying chamber in themanner described above. On their second removal from the drying chamber,the tapes are hung on stands overnight.

The present invention contemplates coating two tapes at a time as wellas coating tapes which are of various lengths.

The coating material, producing a lacquer-like coating, is preferably acopolymer of vinyl chloride/ acetate resin dissolved in a solventcomprising a ketone or a mixture containing a ketone or ketones, forexample a mixture of acetone and toluene. One suitable such solutioncoating by way of example may comprise 90% by weight of vinyl chlorideand of vinyl acetate in a ketone solution having an intrinsic viscosityof 0.79 and a specific gravity of 1.36. However, other similar vinylchloride/ acetate solution coatings may be employed.

After being hung overnight or, say, for 24 hours, to remove all tracesof solvent, the tapes are calendered and dried. This inventioncontemplates calendering and drying two sets of tapes as well as tapesof different lengths.

I claim:

An improved cigarette machine tape having wear and abrasion resistanceproperties comprising a narrow endless woven fabric tape constituting acigarette machine tape of predetermined length and having fibers, saidfibers having microcrystalline wax impregnated thereon for lubricatingthe fibers to reduce wear of the tape caused by the flexing of the tapefibers in the cigarette machine, and an external layer of lacquer of acopolymer of vinyl chloride/ vinyl acetate resin on both sides of thetape for providing a protective layer for said wax and said fibers. 45

References Cited by the Examiner UNITED STATES PATENTS 2,184,600 12/1939Knup et al. 11776 2,227,787 1/1941 'Laufer 11792 2,306,046 12/1942Duggan et al. '11792 X 2,800,701 7/1957 Watts et al. 74232 3,023,4823/1962 Gilboy et al. 11776 X WILLIAM D. MARTIN, Primary Examiner.

JOSEPH B. SPENCER, RICHARD D. NEVIUS,

Examiners.

